Hi, guys. I’m recently using CFD to simulate NREL Phase VI wind turbine with a commercial software named SC/Tetra. Somehow the torque generation disobey the experiment, it goes down when the wind speed increase. However, when I took away the rotation, torque did increase with wind speed. I had checked geometry and analysis condition, no problem was found. I built another turbine using different airfoil and size, almost the same set-up. Then compared computational result with BEM theory and they match pretty much. Can anyone give me suggestions on what might be the problem? Thank you.

I am not sure about the simulation technique that you are using. But in general it is not necessary that the torque should increase with wind speed. For every turbomachine there will be an optimum fluid speed for maximum torque.

When you take away the rotations, I guess the torque should increase more faithfully with the wind speed. That part is fine.

That's what I'm wondering. I even tried self-design blades and flat plates, the torque all increased with wind speed. However, when it comes to the Phase VI turbine blades, it just gave me ridiculous results.

Tell me one thing.... Do you set the rotation speed of the blades... or let it rotate at some speed on its own under some given load........ I am asking cause as such I do not know much about wind turbine simulation.